From: Sasha Levin Date: Thu, 15 Nov 2012 20:51:46 +0000 (-0500) Subject: prevent stack buffer overflow in host_reset X-Git-Tag: v3.2.36~84 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=567fd40fe65a51594d7745827226f93d9a40ec6f;p=pandora-kernel.git prevent stack buffer overflow in host_reset commit 072f19b4bea31cdd482d79f805413f2f9ac9e233 upstream. store_host_reset() has tried to re-invent the wheel to compare sysfs strings. Unfortunately it did so poorly and never bothered to check the input from userspace before overwriting stack with it, so something simple as: echo "WoopsieWoopsie" > /sys/devices/pseudo_0/adapter0/host0/scsi_host/host0/host_reset would result in: [ 316.310101] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff81f5bac7 [ 316.310101] [ 316.320051] Pid: 6655, comm: sh Tainted: G W 3.7.0-rc5-next-20121114-sasha-00016-g5c9d68d-dirty #129 [ 316.320051] Call Trace: [ 316.340058] pps pps0: PPS event at 1352918752.620355751 [ 316.340062] pps pps0: capture assert seq #303 [ 316.320051] [] panic+0xcd/0x1f4 [ 316.320051] [] ? store_host_reset+0xd7/0x100 [ 316.320051] [] __stack_chk_fail+0x16/0x20 [ 316.320051] [] store_host_reset+0xd7/0x100 [ 316.320051] [] dev_attr_store+0x13/0x30 [ 316.320051] [] sysfs_write_file+0x101/0x170 [ 316.320051] [] vfs_write+0xb8/0x180 [ 316.320051] [] sys_write+0x50/0xa0 [ 316.320051] [] tracesys+0xe1/0xe6 Fix this by uninventing whatever was going on there and just use sysfs_streq. Bug introduced by 29443691 ("[SCSI] scsi: Added support for adapter and firmware reset"). [jejb: added necessary const to prevent compile warnings] Signed-off-by: Sasha Levin Signed-off-by: James Bottomley Signed-off-by: Ben Hutchings --- Reading git-diff-tree failed